Dacryocystocele
Contents
Synonyms:
Nasolacrimal duct cyst, Amnioticocele, Amniocele.
Definition:
Dacrycystocele is a cystic lesion involving the tear out flow tract due to obstruction distal to the level of lacrimal sac. The common site of obstruction being at the level of nasal end of naso lacrimal duct (i.e. at the level of inferior turbinate).
Etiology:
1. Failure of complete canalization of the nasolacrimal duct. The nasolacrimal drainage system starts to develop during the third month of intrauterine life. It is initially seen as a cord of epithelium between the maxillary and fronto nasal processes. This cord of epithelium becomes canalized uniformly throughout its length. Communication with the inferior meatus occur by the 6th month of intrauterine life.
2. Persistence of the membranous barrier at the level of Hasner's valve.
Pathology:
For congenital dacryocystocele to occur two things is a must:
1. Imperforate naso lacrimal duct distally and
2. Valve like obstruction at the junction of common canaliculus and lacrimal sac proximally. As a result of this obstruction fluid starts to accumulate within the nasolacrimal duct system distending it proximally. Distension of sac compresses the canalicular system further causing a functional trap door like block. This functional obstruction can be confirmed by using lacrimal sac probe. No anatomical barrier can be demonstrated when an attempt is made to probe the nasolacrimal system.
Incidence:
1. Common in female infants
2. Common in whites
These features suggest a genetic predisposition.
Clinical features:
Congenital dacryocystocele can be unilateral / bilateral. These are cystic lesions, present at birth. This could infact become apparent during the first few weeks of life when the tear secretion increases. Affected infants present with a bluish colored cystic mass in the medial canthal region. Compression of this cyst with fingers usually fails to result in the reflux of tears through the lacrimal puncta.
Infants with congenital dacryocystocele are at risk for secondary infection of the eye / orbit. This is due to the absence of the well defined facial layer that separates the lacrimal sac from the orbit. This is normally present in older children and adults.
A combination of acute dacryocystitis, peri orbital cellulitis / orbital cellulitis in neonatal age group should raise suspicion of presence of congenital dacryocystocele.
Congenital dacryocystocele always has a nasal component. A cystic mass over the inferior meatus. Since infants are obligate nasal breathers, bilateral naso lacrimal cysts can cause life threatening airway obstruction, i.e. something similar to choanal atresia. All children with congenital dacryocystocele should have a complete nasal examination done with a nasal endoscope. This cyst should be differentiated from nasal dermoid cysts, nasal gliomas etc. Nasal mass in these patients are soft and compressible when palpated with a nasal probe. CT scan / MRI scanning: will help in differentiating these lesions from nasal dermoids / meningoencephaloceles.
Management:
Depends on whether the dacryocystocele is a complicated or an uncomplicated one. Uncomplicated dacryocystoceles can be managed conservatively. Surgery is indicated if it is complicated with acute / chronic dacryocystitis. If the external medial canthal cyst is large it can cause corneal astigmatism with the impending risk of amblyopia. If the intranasal component causes respiratory obstruction then surgery is a must to save the patient.
Role of topical antibiotics:
Topical antibiotics can be used to prevent secondary conjunctivitis. Warm compresses, lacrimal massage, probing of lacrimal duct can be performed to facilitate drainage of tears.
Role of probing:
Probing should be attempted only when other conservative procedures fail. For probing to be effective it should relive both the functional proximal obstruction and the complete or incomplete distal obstruction.
Surgery:
1. Endoscopic marsupialization of nasal component of Dacryocystocele. After this decompression procedure the proximal one way valve of Rosenmuller should be able to function normally.
